...Walking the streets I usually keep it in the middle, about medium sized, and focus (half press and hold) and recompose....

That's the way I've been doing it with the X100 and have had great success. Perhaps it's a habit left over from shooting MF film cameras where the split was always in the center. You didn't have much choice but to focus and recompose.

I'm sure I read somewhere that with Contrast Detect AF systems unlike Phase Detect ones on SLR's, you should NOT focus on the boundary between subject and background e.g. strong vertical lines.

With a Phase Detect system this is what you would normally do for focus. Because a Phase Detect system can measure distance, it knows what is in the foreground.

With a Contrast Detect system it doesn't measure distance so has no idea which is front or which is back, so can pick either. So, you should ensure no background falls into your focus area if you want accurate focusing.

Looking at the second image, based on what is in focus - shop's pavement signs and (very nearly) the pedestrian with toddler-in-arms BEHIND the main subject - the plane of sharp focus is clearly some way in front of your intended target.

Both the X100 and (apparently) now the X100s suffer from 'weird AF box syndrome'. Spoilt a lot of shots - as even the slightest overlap can see the camera homing in on a more distant target.

How on earth could it fail to lock on to the object? The AF box was at its largest in the middle of the frame and had gone green*. I have two other frames on either side of the last one, both of which are similarly out of focus. I wasn't keeping a half press on the shutter button, either.

I had seen a few examples in previous testing that made me very slightly nervous, but this is just unacceptable to me (YMMV). If I can't trust the camera to get such a straightforward subject right, then I can't trust it at all. At least with my old X100 I was used to using manual focus and the AFL button... If I'm going to be using that process then I don't see the point of upgrading.

I must stress that this in no way invalidates the X100S for anyone else. It's capable of great things. But, for me, the AF still has too far to go.

* I checked in playback and the focus was square on the man's neck and the baby

I'm really sad to say this as a massive Fujifilm X-Series fan, but that's my conclusion too. I borrowed an X100S and compared it side by side with my X100. In a lot of circumstances the X100 actually locked focus quicker than the X100S!!

The only time the X100S seriously out-performed the X100 was at close-range (30-50cm) in good light, then the difference was so great that you'd be hard pressed to think they were related, but anything outside of that the X100 was at least and good and to my huge surprise actually was faster than the X100! I found this both in the real-world and in my studio tests - I'll be posting up a video onto YouTube about it soon.

The other issue is that the colours are not as rich coming out of the X100S with the same settings. I heard that the X100S had lost the X100 'look' but I didn't believe until I tried it for myself!

How on earth could it fail to lock on to the object? The AF box was at its largest in the middle of the frame and had gone green*. I have two other frames on either side of the last one, both of which are similarly out of focus. I wasn't keeping a half press on the shutter button, either.

I had seen a few examples in previous testing that made me very slightly nervous, but this is just unacceptable to me (YMMV). If I can't trust the camera to get such a straightforward subject right, then I can't trust it at all. At least with my old X100 I was used to using manual focus and the AFL button... If I'm going to be using that process then I don't see the point of upgrading.

I must stress that this in no way invalidates the X100S for anyone else. It's capable of great things. But, for me, the AF still has too far to go.

* I checked in playback and the focus was square on the man's neck and the baby

I'm really sad to say this as a massive Fujifilm X-Series fan, but that's my conclusion too. I borrowed an X100S and compared it side by side with my X100. In a lot of circumstances the X100 actually locked focus quicker than the X100S!!

The only time the X100S seriously out-performed the X100 was at close-range (30-50cm) in good light, then the difference was so great that you'd be hard pressed to think they were related, but anything outside of that the X100 was at least and good and to my huge surprise actually was faster than the X100! I found this both in the real-world and in my studio tests - I'll be posting up a video onto YouTube about it soon.

The other issue is that the colours are not as rich coming out of the X100S with the same settings. I heard that the X100S had lost the X100 'look' but I didn't believe until I tried it for myself!

Boy, I wish I had a $1 for every sweeping, doom & gloom post I've read about a new camera barely days in the market.

I wish I had $2 for every such post by someone who didn't even own the camera ...

Maybe it's my age. As someone who is both an engineer and who grew up with cameras that did not focus themselves at all, I appreciate both reliable data as well as the limitations of technology. Were there no limits, I believe there would also be no art.

Boy, I wish I had a $1 for every sweeping, doom & gloom post I've read about a new camera barely days in the market.

I wish I had $2 for every such post by someone who didn't even own the camera ...

Maybe it's my age. As someone who is both an engineer and who grew up with cameras that did not focus themselves at all, I appreciate both reliable data as well as the limitations of technology. Were there no limits, I believe there would also be no art.

My <$0.02 ...

jeb

Normally I'd be the first to agree with you, there is too much talk about the unnecessary minutia of cameras, but when the replacement is worst than the predecessor on a subject that Fujifilm says it is better at, I think it's kind of important to be honest and point it out!

I'm the biggest Fujifilm fan out there, I wouldn't say this lightly without qualifying it. As it stands, the AF on the X100S is only better under one specific set of circumstances, so it's just not worth upgrading at this point.

It FW 1.01 the problem? Initial reports by several reviewers, who presumably were running 1.00, or even pre-release FW, were that the AF was quicker than the X100's. I think we need a little patience to see how Fuji sorts this out.

What about the AA-filter for the X100s and the X100. Isn't this a big difference between the two (along with the 16mp vs 12mp)? Probably less noise level in the end and you can turn up the ISO for a more steady shot, in combination with the smaller focus box

If you shoot RAW and find the output of the X100s lacking some color in comparison, a bump up in saturation in PP would solve that, not? And in Jpeg, in camera?

Please look at the images at 1:1. The first clearly suffers from camera shake. Look at the lettering on the signs to the right of the subject and the logo on the subjects hat. Clearly camera shake not OOF.

And on the second I believe Zach's comment is absolutely spot on. I have learned to put the AF entirely on my subject with a strong contrast line within that same plane. For some months after I got my early delivery X100, I thought the strong vertical line I needed was the vertical edge of the subject and I was mightily disappointed because more often than not the object in focus was the background.

Practice with a small box and get at least 90+% of the box on the subject that is in the plane of focus you want. If the CDAF can it will focus on the background. If you don't allow that box to see any of the background you have solved that problem.

PS: I don't know a thing about the 100S as I only have the 100 and am not likely to "upgrade" any time soon.